Hempcrete is an eco-friendly, game-changing material for building sustainable and environmentally beneficial structures. This well-supported biocomposite material is made from hemp hurds, the core fibres of the hemp plant, which are combined with lime and water. It is a green alternative to ordinary concrete, which has stimulated interest in eco-friendly construction. Hempcrete is a highly effective insulator with exceptional qualities. As a timeless choice for evolving modern designs and meeting the needs of industries, this material is in high demand at present as well as in the future.
This blog will provide readers with useful information about hempcrete blocks, including their benefits, manufacturing process, and uses.
What is Hempcrete?
Hemp is an excellent plant that is planted for industrial and medicinal purposes and requires only a small amount of water. This can be cultivated without the use of any chemical fertilisers or pesticides and also supports regenerating agricultural land. When hemp and lime are combined, a natural concrete, hempcrete is produced with extremely lightweight properties. Its thermal mass and vapour permeability help create high-performance buildings that meet current and future thermal regulations.
Buildings of many kinds, including homes, apartment complexes, public and service sector buildings, and other structures, can be constructed, renovated, and restored using hempcrete, one of those bio-based materials.
The Composition of Hempcrete
In construction, an environmentally friendly building material that is made from hemp shives, lime, and water, is hempcrete. This lightweight, insulating substance is manufactured by combining woody hemp fibres, or hurds, with lime as a binder. Either natural hydraulic lime or hydrated lime is commonly found in the lime-based binder.
During the carbonation process, CO2 is absorbed by hydrated lime, which is formed from pure limestone. The setting period for hempcrete is shortened to around two weeks to a month for sufficient strength by combining hydraulic binders with ordinary hydrated lime for quicker results.
A small amount of cement or pozzolanic binder can be added to speed up the setting time. This makes the product lightweight, strong, durable, and suitable for constructing structures that are sustainable and long-lasting.
Benefits of Hempcrete Construction
The ideal benefits of hempcrete construction are the following:
- Hemp absorbs carbon as it grows, offsetting the carbon released during hempcrete production, making it a carbon-negative material.
- It makes structures safe and resistant to fire.
- Since hempcrete doesn’t require any additional chemicals, it produces a healthy interior environment.
- Hempcrete is an excellent material; it handles temperature swings so well and provides great thermal insulation.
- When the relative humidity is high, hempcrete absorbs moisture; when it is low, it releases it.
- It is impervious to termites and other pests.
- Compared to conventional cement, hempcrete uses less water throughout the processing stage.
- Its strength and features increase with time because it takes decades to cure completely.
Applications of Hempcrete in Construction
The following are some of the uses for hempcrete blocks:
- For both exterior and interior walls, hempcrete blocks provide efficient insulation.
- They are used on roofs and floors for their excellent insulation properties.
- Under flooring, hempcrete is used as a supporting material.
- In addition to providing insulation, it is used as a plastering medium.
- Hempcrete blocks are frequently used while constructing new structures.
- They improve the insulating qualities of older structures through retrofitting.
- Hempcrete is used to restore and renovate a variety of structures and buildings.
Properties of Hempcrete
Hempcrete’s numerous engineering qualities include:
- Hempcrete is strong and long-lasting.
- Its lightweight is one of its defining characteristics.
- Hemp lowers the carbon footprint by absorbing carbon dioxide.
- By lowering building temperatures and humidity, the material helps to improve thermal comfort and reduce energy use.
- Because of its low density and ability to withstand cracking, hempcrete is advised for seismically vulnerable locations.
- The material’s low compressive strength of 1 MPa, or one-twentieth of conventional concrete, renders it unsuitable for use in building foundation construction in seismically active areas.
Production Process of Hempcrete Blocks
Hempcrete is processed using three fundamental steps.
- Mixing the raw materials:
To make the best mixture, raw ingredients, including water, hemp shives, and a lime-based binder, are blended proportionately.
- Moulding the Mixture:
The mixed raw materials are poured into moulds and shaped into blocks, typically 6 to 30 cm wide.
- Curing the Hempcrete Blocks:
The blocks are put on a conveyor belt to cure once they have reached a firm state. After that, they are transferred to a specific location for outdoor drying. Curing, which usually takes 6 to 10 weeks, depending on the block’s width, improves the block’s strength and hardness.
Advantages of Hempcrete Blocks
The benefits of hempcrete blocks are numerous, as follows:
- Hempcrete is an eco-friendly, energy-efficient building material with a carbon footprint of -72 kg/m².
- Blocks of hempcrete show good fire resistance.
- Hempcrete blocks have a very high capacity to handle moisture.
- Hempcrete blocks come in different sizes (widths) and have a wide range of uses.
- The strength and longevity of hempcrete bricks are its defining characteristics.
- Because they are lightweight, transporting is made easier.
- Blocks of hempcrete help control the structure’s temperature.
- These blocks are sometimes used in ornamental construction.
Disadvantages of Hempcrete Blocks
The following are the drawbacks of hempcrete blocks:
- Because of its reduced compressive strength, hempcrete is not a good choice for foundation construction.
- Its use in some constructions is limited because it is not advised for components that are subjected to high loads.
- Due to its limited popularity in many nations, hempcrete is used less frequently overall.
- It might be challenging to source hemp because it is not always available or grown.
- A lack of awareness about hempcrete construction among builders, engineers, and architects is a result of its limited appeal.
- It is comparatively more expensive than conventional concrete.
- Because hempcrete blocks are larger than conventional concrete blocks and brickwork, larger areas may be used, and less carpet and buildup area will be provided.
Conclusion
In the form of hempcrete blocks, this blog explained every facet of hempcrete and its potential as a building material. The definition, uses, manufacturing process, benefits, and drawbacks of hempcrete were all covered in the course of the discussion to help understand all about hempcrete.